After years of unconditional, fierce love (which generally extends to taking down anyone who dares to criticize anything JB does), Bieber faced the unusual sound of boos on Monday night after he took the stage far after he was scheduled for a show at London's O2 Arena.

i was 40 min late to stage. there is no excuse for that and I apologize for anyone we upset. However it was great show and Im proud of that

According to BBC News, Bieber, 19, faced the sight of frantic parents arriving at the venue expecting to pick up their children at the same time he was finally taking the stage. Some fans reportedly booed an hour before Bieber began the show after they were treated to an endless loop of Michael Jackson songs and no explanation for the late start.

Early Tuesday morning (March 5), Bieber posted a series of apologies to his fans, blaming them on unspecified production issues. "Last night I was scheduled after 3 opening acts to go on stage at 9:35, not 8:30," he explained, disputing reports that he got started two hours late.

"But because of some technical issues I got on at 10:10 ... so ... I was 40 min. late to stage," he wrote. "There is no excuse for that and I apologize for anyone we upset. However it was [a] great show and I'm proud of that."

Further, Bieber promised that Tuesday night's show would run on time. "My relationship with the media is not always easy, but I'm trying," he added. "I'm all about the music and the performance and I respect my fans. I never have any intent to upset or let anyone down. And I'm not okay with things being exaggerated. Once again sorry for anyone upset."

Before the apologies, a number of parents vented about the show to BBC News.

One claimed the opening acts finished around 8:50 p.m. local time and Bieber didn't take the stage until after 10:30 p.m. "A few of the parents went up to the information desk to complain and they were saying there's nothing they could do and that 'It's just Justin Bieber's production team,'" said mother Tracey Wilson. She complained that many in the crowd needed to catch the last trains home, some of which left just a half hour after the show started.

Another parent, who paid nearly $600 for three tickets said that he ended up missing the concert so he could catch the last train. "Disgusting! Waste of my time and money ... never again," tweeted Wayne Parsonage. The father of a young girl whose bedroom is covered with Bieber posters and who had a concert countdown on her phone said his daughter was "inconsolable" after they were only able to catch 15 minutes of the show before dashing to the train station. There were numerous reports of children who fell asleep in their seats or on parent's shoulders while they waited for the star to come out.

Bieber was reportedly due to begin his set at 8:30 p.m. and wrap by 10:15 p.m. to accommodate the many young fans in the audience. And when Bieber did get things going, attendees said he had to cut nearly a half hour out of the set to avoid hitting a curfew time.

A spokesperson for Bieber could not be reached for comment at press time to elaborate on the technical issues. The venue did post one tweet, saying, "Justin Bieber is now on stage and apologizes for the lateness of his show," ensuring Beliebers that the London subway would still be running when the show ended. That was followed by another tweet Tuesday morning that read, "Exploring all available options to ensure this doesn't happen again."

Earlier in the day, Bieber had been tweeting excitedly about the first of three shows this week at the O2, writing, "In a good mood. Got my friends and team with me here and ready for Day 1 at the O2," he wrote. "London get ready! #BELIEVEtour."